1 files changed, 9 insertions, 6 deletions
diff --git a/synapse/storage/databases/main/relations.py b/synapse/storage/databases/main/relations.py
index ce7bfd5146..419b2c7a22 100644
--- a/synapse/storage/databases/main/relations.py
+++ b/synapse/storage/databases/main/relations.py
@@ -384,14 +384,17 @@ class RelationsWorkerStore(SQLBaseStore):
         def get_all_relation_ids_for_event_txn(
             txn: LoggingTransaction,
         ) -> List[str]:
-            rows = self.db_pool.simple_select_list_txn(
-                txn=txn,
-                table="event_relations",
-                keyvalues={"relates_to_id": event_id},
-                retcols=["event_id"],
+            rows = cast(
+                List[Tuple[str]],
+                self.db_pool.simple_select_list_txn(
+                    txn=txn,
+                    table="event_relations",
+                    keyvalues={"relates_to_id": event_id},
+                    retcols=["event_id"],
+                ),
             )
 
-            return [row["event_id"] for row in rows]
+            return [row[0] for row in rows]
 
         return await self.db_pool.runInteraction(
             desc="get_all_relation_ids_for_event",